The present invention relates generally to locking mechanisms for casement windows. More specifically, the present invention relates to an improved lock handle assembly or actuator assembly for a casement window lock. Still more specifically, the present invention relates to an improved lock handle assembly or actuator assembly for installation on wood casement windows.
Casement windows are known. In the past, the locking of a casement window sash to a window frame has been problematic because casement window sashes have a tendency to warp with age and therefore it can be difficult to hold an entire side edge of a sash against a frame for locking purposes. Further, casement window operators typically apply the closing force to only one end of the casement window sash, e.g. the bottom end, and therefore there is a tendency for one end of the sash to engage the frame before the opposing end of the sash. As a result, the side edge of the sash that is to be locked against the frame does not engage the frame all at once thereby making the sash difficult to lock.
To overcome these problems, tie bars have been employed along the edge of the frame to lock the sash against the frame. The tie bars typically include a plurality of rollers mounted on the tie bar that engage ramped keepers spaced along the edge of the window sash. To overcome the warping problem discussed above, the rollers and keepers are appropriately spaced so that the rollers engage the keepers in a sequential manner, starting from the bottom of the sash and ending with the top of the sash. As a result, the bottom of the sash is locked first and the sequential interaction of the middle and top rollers with the middle and top keepers respectively results in the middle and top portions of the sash being pulled against the frame and locked shut.
However, due to the success and wide acceptance of such sequential locking mechanisms, these locking mechanisms are used in a variety of different windows having window frames and window sashes with a variety of dimensions and configurations. As a result, the spacing between the handle or actuator from the tie bar can vary depending upon the manufacturer and window style. Some locks are usable only with certain styles of windows and other window styles require that locks be specifically manufactured for that style. As a result, manufacturing costs can be quite high and the wide variety of locks that are required requires builders to maintain undesirably large inventories of such locks.
A further problem associated with casement window locks employing tie bars is the relative ease in which such locks can be picked. Specifically, in many prior art casement window locks, an intruder can pick the lock or force the lock open by sticking a sharp object between the sash and the frame, engaging the tie bar and pushing downward. Many casement window locks will easily open up upon the application of downward pressure on the tie bar because the handles for casement window locks are not held or retained in place and are typically free to move from the locked to the open position. Further, any attempt to employ a retainer or a latch to hold the handle in the closed or locked position would adversely affect the aesthetics of the handle and escutcheon assembly.
Still further, aesthetic demands have required the handle and escutcheon to have a relatively low profile on the inside surface of the frame. Escutcheons that protrude outwardly from the inside surface of the frame more than xc2xexe2x80x3 are not preferred by consumers and interior designers because they present a prominent appearance on the inside surface of the frame. Instead, consumers and interior designers prefer a low profile escutcheon/handle combination that attracts little notice.
However, while aesthetics demand a low profile, functionality often demands that the handle be able to rotate 180xc2x0 in order to impart a sufficient amount of linear travel to the tie bar. As a result, currently available lock handle assemblies are not able to provide a combination of a low profile for the handle and escutcheon in combination with a 180xc2x0 rotation of the handle.
Therefore, there is a need for an improved lock handle assembly for casement windows that can be utilized on a variety of window designs, that is relatively pick proof or xe2x80x9cjimmyxe2x80x9d proof and further that provides a combination of a low profile for the escutcheon and handle with a sufficient amount of lever throw resulting in a sufficient amount of linear travel for the tie bar.
Still further, the entire locking mechanism including the lock handle assembly is often installed in a wooden window frame prior to shipment of the window to a construction site. As a result of this pre-installation, the handles of the lock handle assemblies are prone to breakage during shipment and handling. Accordingly, there is a need for an improved lock handle assembly for casement windows with a detachable handle which can be detached from the assembly during shipment and easily re-attached at the construction site.
The present invention provides an improved lock handle assembly for casement windows that satisfies all of the aforenoted needs. Specifically, the lock handle assembly of the present invention can be used with a wide variety of different casement window frames due to its use of a connecting link between the tie bar and the lock handle mechanism. Further, the inventive drive gear link of the present invention provides a xe2x80x9cover centerxe2x80x9d condition relative to the central point of rotation which makes the lock handle assembly of the present invention especially difficult to pick or jimmy. Still further, the lock handle assembly of the present invention includes an escutcheon that has a low profile with respect to the inside surface of the window sash but still permits the handle to rotate through an arc sufficiently large enough to enable the axis, where the connecting link is pivotally connected to the drive gear link, to rotate through an arc sufficiently large enough to impart a linear travel to the tie bar in excess of 1.50xe2x80x3. Finally, to facilitate painting of the window frame, the handle is only detachably connected to the assembly and can be removed during painting.
In an embodiment, the present invention provides a lock handle assembly for a casement window that has a movable sash received in a frame. The frame includes a cavity as well as an inside surface. The lock handle assembly comprises an escutcheon which comprises an inner side and an outer side. The escutcheon is securable to the frame inside the cavity with at least a portion of the inner side of the escutcheon being disposed at the inside surface of the frame. The escutcheon further comprises an upper wall and a lower wall with an elongated recess disposed therebetween for receiving a handle. The handle extends into the recess and comprises one end connected to a drive disk. The drive disk is pivotally connected to a fixed gear plate at a rotational axis. The fixed gear plate is connected to the frame, inside the cavity opposite the escutcheon. The fixed gear plate comprises an arcuate gear segment. The drive disk is also connected to the drive gear link. The drive gear link comprises a proximal end and a distal end. The proximal end of the drive gear link comprises an arcuate gear segment in mesh with the arcuate gear segment of the fixed gear plate. The distal end of the drive link is connected to a connecting link at a connecting axis. The upper and lower walls of the escutcheon define a range of rotation for the handle that extends through an angle ranging from about 100xc2x0 to about 140xc2x0. Further, the connecting axis, where the connecting link is connected to the drive gear link, moves through an arcuate path extending through an angle ranging from about 140xc2x0 to about 180xc2x0.
In an embodiment, the upper and lower walls extend towards each other as they extend from the inner side towards the outer side of the escutcheon.
In an embodiment, the angle through which range of rotation of the handle extends ranges from about 110xc2x0 to about 130xc2x0.
In an embodiment, the angle through which range of rotation of the handle extends is about 120xc2x0.
In an embodiment, the angle through which the arcuate path of the connecting axis extends ranges from about 150xc2x0 to about 170xc2x0.
In an embodiment, the angle through which the arcuate path of the connecting axis extends is about 160xc2x0.
In an embodiment, the handle is detachably connected to the drive disk.
In an embodiment, the one end of the handle that is connected to the drive disk comprises at least one prong and the drive disk comprises at least one recess for frictionally receiving the prong of the handle thereby detachably connecting the handle to the drive disk.
In an embodiment, the drive disk comprises a protruding member that extends outward from the rotational axis, the protruding member being connected to the drive gear link.
In an embodiment, the one end of the handle that is connected to the drive disk is forked and comprises two spaced apart prongs, the drive disk comprises two recesses disposed on opposite sides of the rotational axis, each recess for frictionally receiving one of said prongs thereby detachably connecting the handle to the drive disk.
In a preferred embodiment, the linear travel imparted to the tie bar exceeds 1.50xe2x80x3 and, in a preferred embodiment, is about 1.89xe2x80x3 or greater. Manipulation of the gear segments, i.e. the gear segment of the fixed gear plate where the gear segment of the drive gear link, can either increase or decrease the linear travel available. In any event, a sufficient linear travel to the tie bar is provided by the present invention so as to make the handle assembly of the present invention suitable for sequential locking systems with two, three or four roller/keeper pairs.
In a preferred embodiment, the drive disk is connected to the distal end of the drive gear link at a point that is offset from the connecting axis, or where the distal end of the drive gear link is connected to the connecting link. This offset relationship creates a xe2x80x9cover centerxe2x80x9d condition which makes the lock handle assembly of the present invention pick or jimmy resistant. Specifically, if a downward force is exerted on the connecting link or tie bar when the lock handle assembly of the present invention is in a locked position, the downward force exerted by the connecting link and the distal end of the drive gear link will bias the distal end of the drive gear link towards the escutcheon or towards the inside surface of the window frame. In contrast, this same force also biases the proximate end of the drive gear link away from the inside surface of the window frame towards the exterior of the window. This action is opposite to the action required to open the lock and simply jams the lock in the closed or locked position. As a result, a downward force exerted on the tie bar or the connecting link when the lock handle assembly of the present invention is in the locked position simply jams the lock handle assembly in the locked position and therefore renders the lock handle assembly of the present invention tamper or jimmy resistant.
Further, as noted above, the handle is detachable thereby facilitating any painting operation after the assembly is installed and the handle can be removed for shipment and handling.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon reviewing the following detailed description, drawings and appended claims.